2018 Audi A4 Tires

The 2018 Audi A4 uses three tire sizes across its covered trims: 225/50R17, 245/40R18, and 245/35R19. All three are radial sizes, and the correct one depends on the sub-model and wheel package on the car rather than the model name alone.

A Premium may use 17-inch or 18-inch fitment, while Premium Plus and Prestige models use 18-inch or 19-inch fitment. The safest first check is the wheel diameter actually on the vehicle, especially if it may have been changed from its original setup. After that, compare the proper size against the available tire series and sidewall styles.

The 2018 Audi A4 uses 17-inch, 18-inch, or 19-inch rims, depending on the tire size and trim configuration. A 225/50R17 mounts on a 17-inch rim, 245/40R18 uses an 18-inch rim, and 245/35R19 uses a 19-inch rim.

That rim diameter must match the tire exactly, so it should be confirmed before any tire comparison begins. Once the wheel diameter is settled, rim width also matters because individual products within the same size can carry specific approved width ranges. That becomes especially important if the car has aftermarket wheels rather than the original wheel package.

The 2018 Audi A4 has more than one tire size because different trims and wheel packages use different diameters and profiles. Premium models can use 225/50R17 or 245/40R18, while Premium Plus and Prestige models use 245/40R18 or 245/35R19.

In practical terms, that means the right tire is tied to the exact wheel setup on the individual car, not simply to the year and model. Two A4 sedans parked side by side may need different tires if one has 18-inch wheels and the other has 19s. Checking the current tire sidewall and the wheel diameter prevents ordering the wrong fitment.

Start with the exact tire size already matched to the car’s trim and wheel diameter, then compare construction, tire series, and intended use. The 2018 Audi A4 uses radial tires only, but the available options still vary by brand, load specification, rim-width compatibility, and performance character.

A good selection process balances the visual look you want with the way the car is driven. Some owners will focus on everyday street use, while others may pay closer attention to series differences or special-purpose offerings in a given size. Keeping the correct size and wheel diameter first prevents appearance or brand preference from overriding basic fitment.

Blackwall is the most common sidewall style available for the 2018 Audi A4 across its 17-, 18-, and 19-inch tire sizes. In 245/40R18, there are also options with redline and RWL sidewalls, giving that size a broader appearance range than the 17-inch and 19-inch fitments.

That means sidewall style is partly determined by the wheel package already on the car. An owner with 18-inch wheels has the most visual variety, while 17-inch and 19-inch selections stay more conventional. Sidewall treatment should be chosen after confirming the correct size, since appearance options do not override the need to match the proper wheel diameter and fitment.

BFGoodrich and Nitto both offer tires for all three covered 2018 Audi A4 sizes, while M&H Racemaster and Pro-Trac appear in select 245/40R18 applications. Across those brands, the available lines include g-Force Comp 2 AS, g-Force Sport Comp 2, g-Force Phenom T/A, NT555 G2, Drag Radial, and Street Pro III.

Brand choice is only one part of the decision, because the options also differ by sidewall style and, in some cases, approved rim-width range or load specification. The better comparison starts with the exact size the car needs, then narrows the field by how the car is used and whether the goal is a conventional blackwall look or a more distinctive 18-inch sidewall treatment.

On a 2018 Audi A4, construction is straightforward because the covered fitments are all radial. The visual difference comes less from bias-ply versus radial and more from the wheel diameter, profile height, tread style, and whether the tire uses a blackwall, redline, or raised white letter sidewall.

A restoration-minded owner usually gets the closest period-style result by starting with the exact size already tied to the car’s trim and wheel package. From there, the decision becomes how closely the tire’s appearance matches the intended presentation of the car. If originality matters at a very detailed level, period photos and model-specific Audi references are worth checking before choosing a sidewall style.

Correct tire fitment matters on a 2018 Audi A4 restoration because wheel diameter and tire profile strongly influence the car’s stance and overall presentation. Using the proper 225/50R17, 245/40R18, or 245/35R19 fitment keeps the visual proportions aligned with the wheel package intended for that trim.

It also helps avoid practical issues that can come from mixing the wrong tire size with the wrong wheel diameter. Even on a modern collector car, appearance and fitment work together. A careful restoration approach starts with the exact trim and wheel setup, then refines the choice by brand, series, and sidewall treatment rather than substituting a different size for style alone.

Modifications can absolutely affect tire fitment on a 2018 Audi A4. If the car has aftermarket wheels, altered suspension height, wheel spacers, or body changes, the original relationship between tire size, wheel width, and clearance may no longer match the stock setup tied to 225/50R17, 245/40R18, or 245/35R19.

That is why the actual wheel diameter and width on the car should be checked before choosing a replacement tire. Steering clearance, inner-fender room, and suspension travel also deserve attention, especially on lowered cars. Even when the tire size on paper looks familiar, modifications can change how comfortably that size works in everyday road use.

Before driving a 2018 Audi A4 on new tires, inspect the wheel diameter, wheel condition, valve stems, and basic clearances at full steering lock. It also helps to confirm that all four tires match the intended size for the car’s setup and that inflation is set appropriately for the application.

A short test drive should be followed by another look for any rubbing, vibration, or unusual contact marks. On a car that has been sitting, check suspension wear and alignment condition as well, since a fresh set of tires can quickly reveal existing chassis issues. Regular pressure checks and visual inspections help protect the new tires once they are in service.

Tires on a 2018 Audi A4 should be inspected regularly, not just when tread looks low. A quick check for pressure loss, uneven wear, cuts, bulges, or sidewall damage is worthwhile before longer drives, and a more thorough inspection should be part of routine maintenance throughout the year.

That matters even more if the car is driven infrequently, because aging and flat spotting can develop on vehicles that sit for extended periods. Looking over the tires during washing or fueling makes problems easier to catch early. Any sign of rubbing, repeated air loss, or unusual wear pattern should prompt a closer check of alignment, wheels, and suspension condition.